Self-regulating reciprocator device

ABSTRACT

A device for transmitting pressurized fluid from a supply to receiver means such as a tank or a cylinder or the like, comprises a spool carrying at each end symmetrically opposing pistons of diameter larger than the diameter of the third piston located in the middle of said spool, the spool being moved in either direction by the working fluid pressure acting upon said spool to alternatingly feed either one or another port in the housing or to feed and to exhaust the transmitted fluid by additional ports provided, and in a self-regulated reciprocating action, such as found in the positive displacement pumps or in the fluid power controls such as four-way valves however without external operators such as motor-driving pump or solenoidoperating valve, and serves a multipurpose duty in a variety of applications of this device. Appropriate seals permanently positioned to remain engaged with pistons in all operating conditions are employed.

United States Patent 3,326,236 6/1967 Beckett Richard S. Pauliukonis6660 Greenbriar Drive, Cleveland, Ohio 44130 July 16,1969

Mar. 16, 1971 [72] Inventor Appl. No. Filed Patented [54]SELF-REGULATING RECIPROCATOR DEVICE 2 Claims, 4 Drawing Figs.

References Cited UNITED STATES PATENTS Primary Examiner-Alan CohanABSTRACT: A device for transmitting pressurized fluid from a supply toreceiver means such as a tank or a cylinder or the like, comprises aspool carrying at each end symmetrically opposing pistons of diameterlarger than the diameter of the third piston located in the middle ofsaid spool, the spool being moved in either direction by the workingfluid pressure acting upon said spool to alternatingly feed either oneor another port in the housing or to feed and to exhaust the transmittedfluid by additional ports provided, and in a self-regulatedreciprocating action, such as found in the positive displacement' pumpsor in the fluid power controls such as four-way valves however withoutexternal operators such as motor-driving pump or solenoid-operatingvalve, and serves a multipurpose duty in a variety of applications ofthis device. Appropriate seals permanently positioned to remain engagedwith pistons in all operating conditions are employed.

SELF-REGULATING RECIPROCATOR DEVICE The present invention provides adevice for transmitting pressurized fluid from fluid supply to receiverof any choice, such as a tank or an actuating cylinder, with or withoutexhaust means in a housing for escape of the transmitted fluid andwithout the use of external actuators such as motors or solenoidsnormally serving such devices. It is obviously desirable to providedevices of this type which require no external power to actuate, and areextremely simple, reliable and inexpensive. For example, if this deviceis used for fluid pumping as a positive displacement pump, the workingfluid pressure acting upon the spool provided would create the necessaryforce tooperate such pump without the need of conventional pump drivingmeans such as electric motors or the like representing considerablesavings in initial cost and in subsequent operating and maintenancecost.

The present invention provides devices of this general type which aresuitable for use in positive displacement pumps, in fluid power controlssuch as four-way self-regulating reciprocating valves or the like, andwhich enhance design simplicity, reliability and low cost.

These and other objects and advantages of the invention will become morefully apparent from the following description of the embodiment of theinvention, taken together with the accompanying drawings.

In the drawings:

FIGS. la and 1b illustrate cross-sectional views of a device embodyingthe invention combined with position change of a spool and representinga positive displacement pump.

FIGS. 2a and 2b show cross-sectional views with position change of spoolof a four-way self-regulating reciprocating valve of this invention.

Shown in FIGS. 1a and 1b is a pump housing having a continuous centralbore 11 symmetrically bored to receive slidably a symmetrical spool 12with two opposing large diameter pistons 3 and 3a at each spool end anda smaller piston 4 situated midway for entering into the large housingbores 13a and 13b and smaller middle bore 14. At the extreme end of eachlarge diameter bore provisions are made by means of grooves 16 and 16ato receive truarc rings and 15a which serve as spool stops and providean easy spool installation and maintenance means.

The pump housing is provided with fluid infeed port 17 which terminateswith orifice 17a in direct communication with housing bore l4 serving asport 19 feeding means via annulus 1d, and port 21 feeding means viaannulus 20 both cases clearly illustrated in FIGS. la and lb.

Seals 22, 22a and 22b of O-ring configuration or the like and ofappropriate size serve as positive sealing means during the axial spoolsliding when the device is in operation.

Port 17 may be connected to a supply of pressurized hydraulic fluid orother liquid to feed a receiver as shown in FIG. la, the receiver beingconnected to port 19. The fluid flow will proceed from port 17, viaorifice 17a and annulus 18 into the port 19 serving receiver, while port21 is sealed from the fluid supply by the seal 22 secured to piston 4and bore 13b is sealed by seal 22b secured to piston 3.

The operation of this device will initiate when the force created by theworking pressure of the fluid inside the annulus l3 exerts upon piston 3a force difference that overcomes pressure force acting upon opposingpiston 3a including friction created by seals. FIG. 1a indicates thatthe pressure in annulus id is small which usually preceeds a pressurebuildup with fluid influx, at which time increase in fluid flow raisesthe pressure inside the annulus l8 and also pressure acting upon piston3, gradually increasing end force over piston 3 facing annulus l8 andfinally shifting spool to the position illustrated in F lG. 1b when thisforce outbalances resistances present. As can be seen from FIG. llb, thefluid flow now will proceed from port 17 via orifice 17a, annular space24) and into receiver connected to port 21 while port 19 is sealed fromport 17 by a seal 22 and bore 13a is sealed by seal 22a of piston 3a.Again, when the force created by the working fluid pressure insideannulus 20 upon the piston 3a outbalances resistances offered by thepiston 3 force including seal friction, the spool will shift to returnto the original position as shown in FIG. la. Obviously than theshifting of spool by the working fluid pressure will continue for aslong as the supply of fluid prevails and will thus provide aself-reciprocating spool shifting action without aid of externaloperators such as solenoids, motors or other source of powerrlt is alsoobvious that the change of working fluid pressures supplied to thisdevice will either speed up the reciprocating action or slow it down andthat as such will provide a self-regulating mode of operation,satisfying conditions set forth by this invention. Further, it isobvious too that the operation of this pump depends on a single controlelement, such as a simple flow regulator on the infeed line to controlfluid pressures, and a simple shutoff valve for system start and stopfunction, satisfying simplicity parameters entailed in this invention. 1

Shown in FIGS. 2a and 2b are arrangements similar to those identified inFIGS. la and lb with exception of housing 30 which includes additionalports for fluid flow as required by a typical four-way valve in whichspool shifting opens additional exhaust ports 43 and 44 for cylinderone" and cylinder two exhaust respectfully. The spool configuration hereis identical to the spool configuration described when discussing FIGS.la and lb. Also the operation of the device in a fourway valve envelopis identical in terms of pressure forces act ing upon pistons andshifting spool to either cylinder one feeding port 33 while cylinder twoport 41 is exhausting via cylinder two exhaust port 44, or vice versa,and will need no further discussion. The components shown in FIG. 2a and2 are as follows:

valve housing 30 having a continuous central bore 31 symmetrically boredto receive slidably a symmetrical spool 32 with two opposing largediameter pistons 6 and tie at each spool end and a smaller piston 40situated midway for entering into the large housing bores 33a and 33band a smaller middle bore 34. At the extreme end of each large diameterbore provisions are made by means of grooves 36 and 36a to receivetruarc rings 35 and 35a which serve as spool stops and provide an easyspool installation and maintenance means.

The valve housing is provided with fluid infeed port 37 which terminateswith orifice 37a in direct communication with housing bore 34 servingannulus 38 to feed cylinder one" port 39 in FIG. 2a and also servingannulus 50 to feed cylinder two port 41 in FIG. 2b.

Seals 42, 42a and 42b of O-ring configuration or the like and ofappropriate size serve as positive sealing means during the axial spoolsliding and change of spool position during the valve operation.

Ports 44 and 43 serve as cylinder exhaust means. FIG. 2a shows cylinderone being energized by the working fluid flowing from port 37 viaorifice 37a and annulus 38 into port 39 while the cylinder two at port41 is to exhaust via port 44, and the seals 42 and 42b seal off thecommunications with other than ports 37 and 39. FIG. 2b shows spool 32shifted and cylinder one exhausting from cylinder one port 39 via bore43a and cylinder one" exhaust port 43 while the cylinder two" at port 41is feeding via annulus 50 in direct communication with infeed port 37.The position change and cylinder feeding and exhaust in a continuousself-regulated reciprocating action of the spool will continue for aslong as the pressurized fluid enters port 37 to act upon the pistons 6and 6a of this valve.

The invention is not restricted to the slavish imitation of each andevery one of the details described above which have been set forthmerely by way of example with the intent of most clearly setting forththe teachings of the'invention. Obvi' ously, devices may be providedwhich change, eliminate, add certain specific structural details withoutdeparting from the invention.

lclaim:

l. A spool valve device including means defining a bore having arelatively small-diameter central portion and relatively large-diameterend portions, a spool received for reciprocation in said bore, saidspool having a relatively small-diameter upon by fluid pressure betweenthe inlet port and that outlet port which is not blocked by the centralpiston so as to shift the spool.

2. A device as in claim 1, including seals such as O-rings spaced fromeach other along the spool so that each is positioned to remain engagedwith one of said pistons during the spool movement axially under alloperating conditions.

1. A spool valve device including means defining a bore having arelatively small-diameter central portion and relatively largediameterend portions, a spool received for reciprocation in said bore, saidspool having a relatively small-diameter central the spool. and havingrelatively large-diameter end pistons, said pistons being slidable inthe corresponding bore portions, a centrally located inlet port to thebore, at least two outlet ports spaced along the bore on opposite sidesof the inlet port, the central small-diameter piston being arranged toalternately block flow between the inlet port and each of said twooutlet ports as the spool reciprocates in the bore, each of thelargediameter end pistons being arranged to be acted upon by fluidpressure between the inlet port and that outlet port which is notblocked by the central piston so as to shift the spool.
 2. A device asin claim 1, including seals such as O-rings spaced from each other alongthe spool so that each is positioned to remain engaged with one of saidpistons during the spool movement axially under all operatingconditions.